Split System AC & Heat Pump Installation Tips by Frank Wood, TSA
(386) 738-1228 (386)
736-4693 fax
frank.wood@acrgroup.com

Thoroughly inspect all equipment for correct “match” before taking to job site.

Before accepting equipment, thoroughly inspect all equipment for surface or hidden transportation damages.

Review the installation instructions found with each product for safety considerations, correct equipment location and nominal minimum clearances.

Check with your distributor for minimum hurricane “tie down” requirements in your area.

Refrigerant line sets must me properly sized for maximum efficiency and proper oil circulation. Some tips: • reference the outdoor unit (ODU) specifications for standard line set sizing up to a total equivalent (T/E) length of 80’.

• reference the “long line” line set guidelines where line sets exceed T/E length of 80’, exceed 20’ vertical separation and the ODU is more than 10’ higher than the indoor coil (IDC).

• total line set must not exceed T/E length of 200’.
• when ODU is higher than the IDC, vertical separation must not exceed 100’.
• when ODU is lower than the IDC, vertical separation must not exceed 50’.
• line sets exceeding T/E of 80’ require a crankcase heater.

Install the liquid line filter drier provided with the outdoor unit, preferably at the indoor coil away from the outside elements - our only source for moisture removal.

Brazing connections: always use nitrogen while brazing and protect service valves & TXV’s with a “wet rag” or “heat trap”. Note: seals / plastic washers / o-rings & valve cores, etc. should never exceed 250 degrees.

Perform a system evacuation (line set & indoor coil) down to 500 microns. Replace vacuum pump oil daily.

Refrigerant charging tips:

• most favorable charging conditions: outdoor temperature 70 - 100 degrees & indoor temperature 70 – 80 degrees.
• factory charge for 15’ line set. • adjust charge by adding or removing .6 oz/ft of refrigerant above or below a 15’ line set.
• for TXV driven indoor coils, determine target subcooling (S/C) value found on ODU nameplate and use S/C method for charging found in the installation instructions bulletin.
• for “piston” driven indoor coils, use superheat (S/H) method for charging found in the installation instructions bulletin.
• after any charge adjustments, always allow 15 minutes for system to stabilize before declaring a properly charged system.

Thermostat wiring connections at indoor units varies dependent on Model # of FCU, especially ECM variable speed driven units – see installation instruction bulletin.

Indoor blower motor speed selection must be done during startup, don’t assume factory settings are correct for the total external static pressure (ESP) job site conditions – see indoor unit specifications.

Important tools needed on every startup:

• micron gauge
• magnehelic gauge for measuring ESP.
• electronic thermometer with stem & “clamp on” attachments.